Explosive compound



UNITED STATES PATENT OFFICE.

EGBERT JUDSON, OF SAN FRANCISCO, CALIFORNIA.

EXPLOSIVE COMPOUND.

SPECIFICATION forming part of Letters Patent No. 309,787, dated December 23, 1884.

Application filed August 5,18F2 (N0 specimens) To all whom it may concern:

Be it known that I, EGBERT JUDsoN, a citizen of the United States, residing in the city of San Francisco, State of California, have invented a new and useful Improvement in Explosives; and I do hereby declare the following to be a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use it.

The invention relates to that class of explo- 'sives whose force is mainly derived from cheap solid ingredients, prepared in an inexpensive manner-such as nitrates of potash, soda, am monia,bar yta, lead,&c. 1nixed with aproper proportion of carbonaceous matter, and whose decomposition is brought on and hastened by a certain proportion of some comparatively expensive detonating or fulminating sub stance, which I will herein term the-detonate. In this class of powder it is important not only'that theingredients should bear a proper proportion to each other,and should be in afine state of division and thoroughly intermixed, but that, in order to facilitate the spread of the explosive influences, the mass should not be compact, but to a certain extent porous and permeable; and it is also of great agreater or less extent by a peculiar mode invented by me of preparing the cheap materials above mentioned,which mode I proceed to describe by giving one preferred formula and process, out of many which I can use, as follows: Take, by Weight, sulphur, fifteen parts; resin, three partsasphalt, two parts. and stir them weli together. Then take of nitrate of soda seventy-parts, and of anthracite coal ten parts, both being first well pulverized and dried and mixed together. Let these two latter ingredients, preferably when hot, be thoroughly mixed and stirred into the mixture-sulphu-r, resin, and asphaltwhile these latter are in a melted state,taking care that the temperature be not high enough to cause damgel of combustion. The entire mixture should Melt then be thoroughly and constantly stirred until. so cool that the grains cease to adhere to each other. This preparation I term the dope, and it will be found that each of its grains is now enveloped in a coating or covering of varnish composed, as above described, of the sulphur, asphalt, and resin. Moreover, if the nitrate and carbon be extremely fine or pulverulent, the process described will result in the formation of grains of a desirable size for powder by aggregating, agglomerating, or cementing a number of the minute grains into one, thereby increasing the bull: and porousness of the mass, and materially facilitating explosion. Should the nitrate and carbon, however, be more coarsely gronnd,this forination of. grains by aggregation will not take place to any considerable extent,but the grains will then separately receive the benefit of being thus enveloped and protected. Should any lumps remain after cooling, they may be readily broken up or added to the next'batch of material to be treated. v I complete the new explosive by now stirring and distributing, as evenly as possible throughout the mass of the dope, finely-comminuted nitro-cellulose in the proportion of four or five per cent. of its weight, and thus produce a cheap and useful explosive, suitable for all sorts of blasting in which a powder is needed of effective strength between that of common blasting-powder and the ordinary grades of high explosives.

The above formula and process may bewaried-in'many ways.

Any other equivalent detonating or fulminatin g explosive may be substituted for nitro-cellulose, the proportions used being varied according'to its readiness to be detonated.

A less quantity than I have named may be used, down to two or three per cent. ,but I prefer a little more for certainty of explosion; but there must be in all cases enough detonate to 'admitof its complete detonation by the cult nary exploder used in detonating the lower grades of nitro-glycerine powder. reason a larger proportion of the detonate be desired, it may be added at will provided a safe kind be used. As to the fulminates and certain mixtures containing chlorate of potash, it would be dangerous to add a large proportion.

. If for anyv IOO In the composition of the varnishing or coating substance for covering or enveloping the grains of the dopea great variety of substances may be used, and the application of them may be varied in a number of ways. What is specially required for my dope is that its grains shall be covered or enveloped by some coinbustible substance offering resistance to moisture, and also to the absorption of any liquid detonating explosive, provided such be used. Such combustible substance may be liquefied or made pasty by heat or by the application of some solvent or liquid that can be evaporated after mixing with the nitrate and carbon, and in this latter case it could be applied cold, though heat would facilitate the operation. Almost any of the hydrocarbons may be used. Sulphur alone would sufiice. In fact, there is a great variety of combustible substances that will answer for said coating, and can be substituted one for the other, and used either singly or-in combination. If carbon, like anthracite coal, not porous, be used,

it need not necessarily. be coated, though I prefer to have it so. As to the proportion of coating material to be used the best general direction I can give is that it should be enough to envelope all the coarse particles, and to granulate and coat all the fine ones and no more. The result attained is obvious.

The dope, consisting of amass of grains, each of which is enveloped by a coating of resinous or combustible matter, is measurably protected from dampness, and holds the detonate be tween these grains in such manner thatasmall quantity of it is' sufiicient to render its continuitythroughout the mass practically complete, and to insure a perfect detonation and the explosion of the entire compound.

In stating my claim I do not wish to be understood as embracing the mixture of nitroglycerine with my said dope, as this has been already patented to me; but

What I do claim,and desire to secure by Letters Patent, is

The explosive compound made by the mixture of nitro-cellulose or other equivalent detonating or fulminating substance or compound, with the. dope prepared, substantially as and for the purpose set forth;

EGBERT JUDSON Witnesses: R. S. PENNIMAN, ALFRED RIX'. 

